This is a program in which clinical scientists, motivated by clinical problems that affect motor and sensory systems, ask fundamental questions of the nervous system. The studies utilize neurophysiologic and neuroanatomic techniques, and deal with: behavior of motor cortical neurons during experimental hemiparesis; assessment of sprouting and formation of new connections in spinal cord following motor cortical lesions, to elucidate mechanisms of recovery of hemiparesis; comparative studies of sensory inputs to motor and somatosensory cortex in animals and man; electrogenic sources of the motor potential; neuronal mechanisms underlying visual perception, and regulatory effects of the ventral lateral geniculate nucleus on superior colliculus function with particular reference to eye movements. The goals are to elucidate known mechanisms underlying motor and sensory disease states and, when appropriate, extend the basic methodologies to the clinic to aid in management of disease.